Surgical system, device, and method for implanting a surgical device wtihout the use of a guide wire

ABSTRACT

The present invention relates to a system, method, device and kit which utilize a modular pedicle screw implant that does not require the use of a guide wire for implantation and can be assembled in situ. The system, method, device, and kit include a surgical instrument for implanting a modular pedicle screw comprising a cannula coaxially aligned with a modified trocar style instrument or surgical shaft. The surgical shaft contains a first member of a surgical shaft-inner pedicle bone screw member joint, illustrated herein as a locking taper, for securing an inner member of a pedicle screw thereto. The inner member of a pedicle screw is further adapted to couple to an outer pedicle sheath. In combination, the inner member of a pedicle screw and the outer pedicle sheath form a solid modular pedicle screw.

PRIORITY CLAIM

In accordance with 37 C.F.R. 1.76, a claim of priority is included in anApplication Data Sheet filed concurrently herewith. Accordingly, thepresent invention claims priority to U.S. Provisional Patent ApplicationNo. 61/781,860, entitled “SURGICAL SYSTEM, DEVICE, AND METHOD FORIMPLANTING A SURGICAL DEVICE WITHOUT THE USE OF A GUIDE WIRE”, filedMar. 14, 2013. The contents of which the above referenced application isincorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to surgical systems and methods whichutilize implant devices; and more particularly to a system, method anddevice which utilizes a modular pedicle screw implant that does notrequire the use of a guide wire for implantation.

BACKGROUND OF THE INVENTION

The central nervous system, made primarily of the brain and the spine,is a vital part of the human physiology responsible for coordinatingmany aspects of human activity. The spinal cord is made up of a bundleof nerve tissue and acts as a conduit to communicate neuronal signalsfrom the brain to the rest of the body. Protecting the spinal cord isthe spinal, or vertebral, column. Anatomically, the spinal column ismade up of several regions, including the cervical, thoracic, lumbar andsacral regions, each containing a plurality of vertebrae.

While most people have fully functional spinal cords, it is not uncommonfor individuals to suffer some type of spinal ailment. For example,spinal fractures, or vertebra compression fractures, occur when one ofthe bones of the spinal column fractures. Such an event is oftenaccompanied by sudden onset of pain in the back which intensifies whensitting or standing and decreases when lying down. The pain associatedwith vertebra compression fractures can be strong enough to limit theactivities a person can undertake, thereby reducing the overall qualityof life of the individual.

Spinal fusion is a surgical technique used to join two or morevertebrae. Such procedure is common for individuals suffering from avariety of spine related diseases, such as vertebral fracture. Thefusion process typically involves stabilization of the vertebra usingmetallic screws, such as pedicle screws, rods, plates, or cages.Minimally invasive percutaneous techniques currently practiced utilizepedicle screw systems having a cannulated screw in order to use a guidewire for proper placement. U.S. Pat. No. 7,780,706 is an illustrativeexample of a pedicle screw assembly having a cannulated pedicle screw.In these procedures, the cannulated screw is passed over a guide wirewhich was positioned prior to the placement of the screw over the guidewire. While such technique is relatively safe and effective, severalpossible problems are known to exist.

Use of a guide wire in pedicle screw placement poses several possiblerisks to the patient. First, guide wires may advance through softercancellous bone. If such event occurs, severe damage may result to theorgans or vessels. Second, when placing guide wires in position, theyneed to travel a great distance. Such increased distance sometimesresults in the guide wires forming kinks, becoming bound within thescrew. Fixing the problem can be difficult for the surgeon, increasingthe risk of the guide wire being advanced into a critical vessel. Use ofguide wires cause increased length of surgical instruments. Theincreased length makes the instruments more cumbersome, particularlywhen moving around fluoroscopic imaging devices, such as C-arm, whichare critical for percutaneous screw instrumentation. When using guidewires, cannulated screws are required. Since these screws have hollowsections therein, they are inherently less strong than solid screws.Finally, procedures which use guide wires require additionalinstrumentation, such as retraction devices.

Accordingly, what is needed in the art is a pedicle screw system,device, method, and kit that does not require the use of a guide wirefor proper implantation.

SUMMARY OF THE INVENTION

The present invention relates to a system, method device, and kit whichutilize a modular pedicle screw implant that does not require the use ofa guide wire for implantation. As a result, the system, method, device,and kit eliminate the risk of puncture or damaging of organs and vesselsand eliminates the risk of problems associated with guide wire kinkingor breaking. Without the need for a guide wire, surgical proceduresbecome less risky as there are less steps to undertake, and theinstrumentation is smaller, thereby providing more room to accommodateimaging technology. The present invention also provides for moresurgical options for a variety of indications, with the option of aunipolar or multi-polar screw head via one screw system. Finally, thepresent invention provides a low profile, one piece retractor which mayattach to the screw and build off the system for visualization andsurgical decompression.

The system, method and device include a surgical instrument forimplanting a modular pedicle screw comprising a cannula coaxiallyaligned with a surgical shaft. The surgical shaft contains a firstmember of a surgical shaft-inner pedicle bone screw member joint,illustrated herein as a locking taper, for securing an inner member of apedicle screw thereto. The locking taper is designed to provide accuratealignment within and a firm seat into a corresponding second member ofthe surgical shaft-inner pedicle bone screw member joint. The innermember of a pedicle screw is further adapted to couple to an outerpedicle sheath. In combination, the inner member of a pedicle screw andthe outer pedicle sheath form a solid modular pedicle screw that isassembled in situ. The present invention provides a device in which thetrocar style or surgical shaft needle is the actual implant. The tip ofthe surgical shaft forms the center of the solid screw shank. Themodular outer pedicle sheath is placed over the surgical shaft,assembling the solid, guide wireless screw in situ. Once assembly iscompleted, the surgical shaft is designed to be detachable from theimplant.

In an illustrative embodiment, a surgical instrument for implanting amodular pedicle screw without the use of a guide wire is described. Thesurgical instrument comprises a first outer member having a firstproximal end, a second opposing distal end, and an elongated first outermember main body there between; and a second inner member having a firstend, a second end, and an elongated inner member body, said elongatedinner member sized and shaped to rest within said first outer member,thereby forming a coaxial relationship, said first end having a firstportion of a modular pedicle screw attached thereto. The second innermember and the first portion of a modular pedicle screw may be securedtogether via a joint.

In another illustrative embodiment, a surgical system for implanting amodular pedicle screw without the use of a guide wire is described. Thesurgical system comprises a surgical instrument comprising an outercannula having a first proximal end, a second opposing distal end, andan outer cannula main body there between; and a surgical shaft having afirst end, a second end, and a surgical shaft body, said surgical shaftsized and shaped to rest within said outer cannula thereby forming acoaxial relationship, said surgical shaft second end frangibly coupledto a modular bone screw implant; and a threaded modular bone screwimplant outer sheath.

The modular bone screw implant includes a plurality of coupling members,such as but not limned to grooves, sized and shaped to interlock withthe threaded modular bone screw implant outer sheath. The surgicalsystem for implanting a modular pedicle screw without the use of a guidewire may include a modular bone screw implant outer sheath whichcomprise threading having the same thread pitch as the modular bonescrew implant, whereby said modular bone screw implant outer sheathlocks to said modular bone screw implant. The surgical shaft and themodular bone screw implant are secured tighter via a joint, which mayinclude a locking taper and corresponding socket sized and shaped toreceive and hold said locking taper.

In another embodiment, a method of performing a surgical procedure forimplanting a modular pedicle screw without the use of a guide wire isdescribed. The method compromises: forming an opening in the skin of apatient; inserting a surgical instrument for implanting a modularpedicle screw without the use of a guide wire through said opening; anddelivering said surgical instrument to a target area, said surgicalinstrument having an outer cannula having a first proximal end, a secondopposing distal end, and an outer cannula main body there between; and asurgical shaft having a first end, a second end, and a surgical shaftbody, said surgical shaft sized and shaped to rest within said outercannula thereby forming a coaxial relationship, said surgical shaftsecond end frangibly coupled to a modular bone screw implant; removingsaid outer cannula once said surgical instrument has reached said targetarea, whereby when said outer cannula has been removed, said surgicalshaft remains in place at said target site; placing a modular bone screwimplant outer sheath onto the surgical shaft; guiding said modular bonescrew implant outer sheath to said target site by moving said modularbone screw implant outer sheath along said surgical shaft; securing saidouter bone screw implant outer sheath to said modular bone screwimplant, whereby when secured to each other, a solid pedicle screw isformed. One in place, the surgical shaft can be is removed by detachingthe body from the formed solid pedicle screw

Finally, a kit for use in performing a surgical procedure for implantinga modular pedicle screw without the use of a guide wire is described.The kit comprising at least one outer cannula having a first proximalend, a second opposing distal end, and an outer cannula main body therebetween; at least one surgical shaft having a first end, a second end,and a surgical shaft body, said surgical shaft sized and shaped to restwithin said at least one outer cannula thereby forming a coaxialrelationship, said surgical shaft second end frangibly coupled to amodular bone screw implant; and at least one modular bone screw implantouter sheath configured to couple with said modular bone screw implantsecured to said surgical shaft. The kit may include a plurality of outercannula, said plurality of outer cannula being the same size, differentsizes, or combinations thereof; a plurality of surgical shafts, saidplurality of surgical shafts having modular bone screw implants coupledthereto of the same size, different sizes, or combinations thereof; anda plurality of modular bone screw implant outer sheaths, said pluralityof modular bone screw implant outer sheaths being the same size,different sizes, or combinations thereof.

Accordingly, it is an objective of the present invention to provide animproved system, method and device used for inserting surgical implants.

It is a further objective of the present invention to provide animproved system, method and device which does not require the use of aguide wire for implantation.

It is yet another objective of the present invention to provide animproved system, method and device which reduces the risk associatedwith using a guide wire in surgical procedures.

It is a still further objective of the present invention to provide animproved system, method and device for percutaneous pedicle screwprocedures which does not require the use of a guide wire forimplantation and can be assembled in situ.

It is a further objective of the instant invention to provide a system,method and device for percutaneous pedicle screw procedures which doesnot require the use of a guide wire for implantation, can be assembledin situ, and forms a solid screw.

It is yet another objective of the instant invention system and methodof assembling a modular pedicle screw in situ using a modified trocartype instrument for guiding and assembling the pedicle screw.

Other objectives and advantages of this invention will become apparentfrom the following description taken in conjunction with anyaccompanying drawings wherein are set forth, by way of illustration andexample, certain embodiments of this invention. Any drawings containedherein constitute a part of this specification and include exemplaryembodiments of the present invention and illustrate various objects andfeatures thereof.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a perspective view of a surgical instrument for implanting amodular pedicle screw in accordance with the present inventionillustrating a surgical shaft inserted within a cannula;

FIG. 2 is a perspective view of the surgical shaft in accordance withthe present invention;

FIG. 3 is a partial view of the surgical shaft in accordance with thepresent invention;

FIG. 4 is a perspective view of the inner member of the modular pediclebone screw;

FIG. 5A is a perspective view of the outer sheath of the modular pediclebone screw;

FIG. 5B is a perspective view of the modular pedicle bone screw;

FIG. 6 is a cross sectional view of the main body of the outer sheath ofthe modular pedicle bone screw;

FIG. 7 illustrates the insertion of the surgical instrument forimplanting a modular pedicle screw into the pedicle of the vertebra;

FIG. 8 illustrates the removal of the cannula, exposing the surgicalshaft;

FIG. 9 illustrates the insertion of the bone screw shaft, using thesurgical shaft as a guide;

FIG. 10 illustrates the formation of the modular pedicle screw andremoval of the surgical shaft from the patient;

FIG. 11 is an illustrative embodiment of a kit in accordance with thepresent invention;

FIG. 12 is an alternative embodiment of a kit in accordance with thepresent invention;

FIG. 13 is an alternative embodiment of a kit in accordance with thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

While the present invention is susceptible of embodiment in variousforms, there is shown in the drawings and will hereinafter be describeda presently preferred, albeit not limiting, embodiment with theunderstanding that the present disclosure is to be considered anexemplification of the present invention and is not intended to limitthe invention to the specific embodiments illustrated.

Referring to FIGS. 1-6, a surgical instrument for implanting a modularpedicle screw, referred to generally as 10, is illustrated. The surgicalinstrument for implanting a modular pedicle screw 10 is preferablymodeled after a standard Jamshidi style needle. Accordingly, thesurgical instrument for implanting a modular pedicle screw 10 contains afirst outer member, illustrated herein as a cannula 12 and a secondinner member, illustrated herein as a modified trocar style surgicalinstrument shaft, referred to generally as trocar or surgical shaft 14.The cannula 12 contains a proximal end 16, a distal end 18, and anelongated main body 20. The elongated main body 20 is preferably rodshaped, having a generally hollow interior sized and shaped to receivethe trocar or surgical shaft 14. In this orientation, the cannula 12 isco-axially aligned with the surgical shaft 14 to allow for the surgicalshaft 14 to slide within the hollow interior.

A handle 24 attaches to the proximal end 16 via any means known to oneof skill in the art, such as, but not limited to, threading or chemicalfastening. The handle 24 may be ergonomically designed to provide agripping means for the user. To allow for the surgical shaft 14 to beinserted into and removed or separated from the cannula 12, the handle24 contains an opening 26 and a corresponding lumen (not illustrated). Adetachable cap 28 allows the surgical shaft 14 to be easy removed fromthe cannula 12. The cannula 12 and the handle 24 may be made of anysuitable materials for use in surgical procedures, including but notlimited to stainless steel, platinum, or plastics such as thermoplasticssuch as polyether ether ketone (PEEK), or combinations thereof.

Referring to FIG. 2, an illustrative example of the modified surgicalshaft 14 is shown. The surgical shaft 14 contains a first proximal end30, an opposing second distal end 32, and an elongated main body 34. Theelongated main body 34 is preferably rod shaped and solid, and sized tofit and slide within the hollow interior of the cannula 12. The distalend 32 of the surgical shaft 14 secures to an inner member of a modularpedicle bone screw 36A. The inner member of a modular pedicle bone screw36A is designed to secure to an outer bone screw sheath 36B to form themodular pedicle bone screw, referred to in combination as 36, see FIG.5B. As illustrated, the inner member of a modular pedicle bone screw 36Ais a solid elongated body, preferably cylindrical shape, with a sharp orpointed end.

As shown on FIG. 3, the distal end 32 of the surgical shaft 14 containsa first member of a surgical shaft-inner pedicle bone screw memberjoint, illustrated herein as a locking taper 38 having tapered surfaces40. Preferably, the first member of a surgical shaft-inner pedicle bonescrew member joint is frangibly attached to the distal end 32 of themodified surgical shaft 14. The locking taper is designed to provideaccurate alignment with and mate to a corresponding surface so that whenmated, frictional forces are sufficient to prevent rotation with respectto one another and require considerable force to separate. The lockingtaper 38 may include, but is not limited to a Morse locking taper or aJarno locking taper, and may be designed to have a partial coneconfiguration or have a general cone shape having various angles oftapering. The locking taper 38 is inserted into a second member of asurgical shaft-inner pedicle bone screw member joint, illustrated hereinas a matching tapered socket 42 positioned within the surface 44 at theproximal end 45 of the inner member of a pedicle bone screw 36A, seeFIG. 4. While the present invention describes the use of a locking taperand corresponding locking taper socket, other mechanisms to secure thesurgical shaft to a portion of the screw may be used, including thethreading and grooves or the use of male/female connectors.

The distal end 46 of the inner member of a modular pedicle bone screw36A preferably contains a pointed tip end 48. As such, when the cannula12 is placed over the surgical shaft 14, the tip end 48 of the innermember of a modular pedicle bone screw 36A forms the pointed end of thesurgical instrument for implanting a modular pedicle screw 10, thusproviding for the pointed tip to be useful in targeting an implant site,thereby forming a part of the actual implant. The pointed tip end 48forms the center of the pedicle bone screw 36. The outer surface 50 ofthe inner member of a modular pedicle bone screw 36A contains aplurality of finely machined grooves 52 sized and shaped to interlockwith a bone screw shaft 36B, see FIG. 3.

Referring to FIG. 5A, an illustrative example of the bone screw shaft36B of the pedicle bone screw 36 is shown. The bone screw shaft 36Bcomprises a proximal end 54, a distal end 56, and a bone screw shaftmain body 58. The bone screw shaft main body 58 is illustrated having agenerally elongated, tubular shape sized to fit over the inner member ofthe modular pedicle bone screw 36A. Accordingly, the bone screw shaftmain body 58 has a hollow or partially hollow interior 59 to allow forthe inner member of the modular pedicle bone screw 36A to slidablyengage therein. The distal end 56 has an opening 60 allowing the pointedend 48 of the inner member of the modular pedicle bone screw 36A toextend upwardly.

The interior surface 62 contains threading 64 which engages with andsecures to the grooves 52 of the inner member of the modular pediclebone screw 36A. Sliding the bone screw shaft 36B over the inner memberof the modular pedicle bone screw 36A forms the solid bone screw 36. Atthe proximal end 54 of the bone screw shaft 36B is a connector member 66which may be adapted to retain a screw set, locking cap, or spinalimplant rod. The outer surface 68 contains a plurality of threading 70to secure the modular pedicle bone screw 36 to the portion of the bodyinserted therein.

The present invention will further be defined by describing anillustrative example of method of use, see FIGS. 7-10. While thesurgical instrument for implanting a modular pedicle screw is describedfor use in spinal implantation, such use is not intended to be limiting.As such, the surgical instrument for implanting a modular pedicle screwin accordance with the present invention can be adapted and used in anysurgical procedure requiring screw implantation.

Referring to FIG. 7, the surgical instrument for implanting a modularpedicle screw 10 is shown inserted through the skin 72 of patient 74. Toinsert the surgical instrument for implanting a modular pedicle screw10, the patient 74 is placed in a prone position according to standardsurgical procedures. To aid in insertion of the surgical instrument forimplanting a modular pedicle screw 10, imaging or guidance technologysuch as fluoroscopy, is utilized and positioned in according to standardsurgical procedures. After the surgical site has undergone sterilepreparation, the skin 72 is marked and an incision 76 is made. Thesurgical instrument for implanting a modular pedicle screw 10 is usedunder guidance to target and cannulate the target area, illustratedherein as the vertebral body 78. The surgical instrument for implantinga modular pedicle screw 10 is tapped to the desired depth within thevertebral body 78. Once securely in position to the desired depth, thecannula 12 of the surgical instrument for implanting a modular pediclescrew 10 is removed. To perform such procedure, the cap 28 is removedfrom the handle 24. The surgeon lifts the cannula 12 in a direction awayfrom the patient 74, see arrows 80, FIG. 8. Once the cannula 12 isremoved, the surgical shaft 14 with the inner member of the modularpedicle bone screw 36A remains embedded in the pedicle.

With the surgical shaft 14 firmly in place, the main body 34 of thesurgical shaft 14 is used as a guide for placing the bone screw shaft36B onto the inner member of the modular pedicle bone screw 36A, therebyforming the modular pedicle bone screw 36. The bone screw shaft 36B iscannulated to fit over and coaxially align with the already implantedinner member of the modular pedicle bone screw 36A. The inner threading64 positioned within the interior surface 62 of the bone screw shaft 36Bsecures to and locks onto the finely machined grooves on the outersurface of the inner member of the modular pedicle bone screw 36A.Preferably, all components with threading have the same thread pitch toallow for the inner and outer components to move as a single unit. Oncesecured to each other, a solid pedicle screw 36 is formed and iscomparable in strength to single, non-cannulated screws. The threading70 on the outer surface 68 of the bone screw shaft 36B is screwed intoplace over the solid center thereby tapping the pedicle and allowing forremoval as necessary as a standard screw.

The implanted main body 34 of the surgical shaft 14 may serve additionalfunctions. The implanted main body 34 of the surgical shaft 14 may beutilized as a guide through which a cannulated screw head may be placed,either uni-planar or multi-planar. The implanted main body 34 of thesurgical shaft 14 may also function as continued soft tissue retractionfor visualization. Finally, the implanted main body 34 of the surgicalshaft 14 may be used as a guide through which standard instruments areused to distract or compress the space according to surgicalindications. Once the procedures are completed, the implanted main body34 of the surgical shaft 14 is detached (such as through use ofperforation within and around the surgical shaft perimeter, not shown orfor example, constructing the detachable portion to have thinnerdiameter that breaks apart after a predetermined force, such as apredetermined bending force, is applied), leaving the pedicle screwimplant 36 intact and in the proper, desired place.

The present invention further contemplates the use of a kit includingone or more of the following: pre-assembled surgical instrument forimplanting a modular pedicle screw and/or a plurality of individualcomponents. FIG. 11 illustrates a first example of a kit in accordancewith the present invention. The kit 82 includes a sterilizable casehaving the contents of at least one cannula 12, at least one surgicalshaft with a locking member 38 unattached to an inner member of thepedicle screw 36A, a plurality of different sized inner member of thepedicle screws 36A, including 35 mm length 36A¹, 40 mm length 36A², 45mm length 36A³, and correspondingly sized bone screw shafts 36B¹, 36B²,and 36B³. In this arrangement, the surgeon secures the inner member ofthe modular pedicle bone screws 36A to the appropriately sized surgicalshaft with a locking member 38 and cannula 12. FIG. 12 illustrates a kit86 having a sterilizable case 84 having the contents of at least onecannula 12, a plurality of surgical shaft 14 ¹, 14 ², 14 ³ withdifferently sized inner members of the pedicle screw 36, and a pluralityof and correspondingly sized bone screw shafts 36B¹ 36B², and 36B³. FIG.13 illustrates a kit 88 having a sterilizable case 84 having thecontents of a plurality of surgical instrument for implanting a modularpedicle screw 10 ¹, 10 ², 10 ³, each pre-assembled and havingdifferently sized inner members of the pedicle screw 36A, and aplurality of and correspondingly sized bone screw shafts 36B¹ 36B², and36B³.

All patents and publications mentioned in this specification areindicative of the levels of those skilled in the art to which theinvention pertains. All patents and publications are herein incorporatedby reference to the same extent as if each individual publication wasspecifically and individually indicated to be incorporated by reference.

It is to be understood that while a certain form of the invention isillustrated, it is not to be limited to the specific form or arrangementherein described and shown. It will be apparent to those skilled in theart that various changes may be made without departing from the scope ofthe invention and the invention is not to be considered limited to whatis shown and described in the specification and any drawings/figuresincluded herein.

One skilled in the art will readily appreciate that the presentinvention is well adapted to carry out the objectives and obtain theends and advantages mentioned, as well as those inherent therein. Theembodiments, methods, procedures and techniques described herein arepresently representative of the preferred embodiments, are intended tobe exemplary and are not intended as limitations on the scope. Changestherein and other uses will occur to those skilled in the art which areencompassed within the spirit of the invention and are defined by thescope of the appended claims. Although the invention has been describedin connection with specific preferred embodiments, it should beunderstood that the invention as claimed should not be unduly limited tosuch specific embodiments. Indeed, various modifications of thedescribed modes for carrying out the invention which are obvious tothose skilled in the art are intended to be within the scope of thefollowing claims.

1-18. (canceled)
 19. A surgical system for implanting a modular pediclescrew, comprising: a cannula having a first proximal end portion and asecond opposing distal end portion; a surgical shaft having a first endportion and a second end portion, the surgical shaft including a modularbone screw implant frangibly coupled to the second end portion, thesurgical shaft dimensioned to be received within the cannula therebyforming a coaxial relationship with the cannula; and an outer sheathincluding a proximal most end and a distal most end, the outer sheathdefining a hollow interior extending between the proximal most end andthe distal most end, the outer sheath positionable about the surgicalshaft, wherein the outer sheath is securable to the modular bone screwimplant such that an entire length of the hollow interior of the outersheath is occupied by the modular bone screw implant, thereby forming asolid pedicle screw.
 20. The surgical system according to claim 19,wherein the modular bone screw implant includes threads on an outersurface thereof and the outer sheath includes threads on an innersurface thereof that are complimentary to the threads of the modularbone screw implant.
 21. The surgical system according to claim 19,wherein the cannula includes a handle secured to the first proximal endportion thereof.
 22. The surgical system according to claim 21, whereinthe handle includes an opening dimensioned to receive the surgical shafttherethrough.
 23. The surgical system according to claim 22, furtherincluding a cap securable to the first end portion of the surgicalshaft, the cap configured to remove the surgical shaft from the cannulathrough the opening of the handle.
 24. The surgical system according toclaim 19, wherein the modular bone screw implant includes a pointeddistal end portion.
 25. The surgical system according to claim 19,wherein the second end portion of the surgical shaft includes a matingfeature and a proximal end portion of the modular bone screw implantincludes a locking feature, the mating feature of the surgical shaftconfigured to engage the locking feature of the modular bone screwimplant to couple the surgical shaft to the modular bone screw implant.26. The surgical system according to claim 25, wherein the matingfeature of the surgical shaft is a taper and the locking feature of themodular bone screw implant is a tapered socket.
 27. The surgical systemaccording to claim 21, wherein at least one of the outer cannula and thehandle is formed from a material selected from the group consisting of:stainless steel, platinum, and polyetheretherketone.
 28. A surgicalinstrument, comprising: a surgical shaft having a first end portion anda second end portion, the surgical shaft including an inner pediclescrew portion frangibly coupled to the second end portion thereof; andan outer pedicle screw portion including a proximal most end and adistal most end, the outer pedicle screw portion defining a hollowinterior extending between the proximal most end and the distal mostend, the outer pedicle screw portion positionable about the surgicalshaft, wherein the outer pedicle screw portion is securable to the innerpedicle screw portion such that the inner pedicle screw portion and theouter pedicle screw portion are coterminous, thereby defining a modularpedicle screw that is solid along an entire length thereof.
 29. Thesurgical instrument according to claim 28, wherein the inner pediclescrew portion includes threads on an outer surface thereof and the outerpedicle screw portion includes threads on an inner surface thereof thatare complimentary to the threads of the inner pedicle screw portion. 30.The surgical instrument according to claim 28, wherein the inner pediclescrew portion includes a pointed distal end portion.
 31. The surgicalinstrument according to claim 28, wherein the second end portion of thesurgical shaft includes a mating feature and a proximal end portion ofthe inner pedicle screw portion includes a locking feature, the matingfeature of the surgical shaft configured to engage the locking featureof the inner pedicle screw portion to couple the surgical shaft to themodular bone screw implant.
 32. The surgical instrument according toclaim 31, wherein the mating feature of the surgical shaft is a taperand the locking feature of the inner pedicle screw portion is a taperedsocket.
 33. The surgical instrument according to claim 32, wherein thetaper defines at least a partial conical configuration.
 34. The surgicalinstrument according to claim 28, further comprising a cannula having afirst proximal end portion and a second opposing distal end portion, thecannula dimensioned to receive the surgical shaft therein therebyforming a coaxial relationship with the surgical shaft.
 35. The surgicalinstrument according to claim 34, wherein the cannula includes a handlesecured to the first proximal end portion thereof.
 36. The surgicalinstrument according to claim 35, wherein the handle includes an openingdimensioned to receive the surgical shaft therethrough.
 37. The surgicalinstrument according to claim 36, further comprising a cap securable tothe first end portion of the surgical shaft, the cap configured toremove the surgical shaft from the cannula through the opening of thehandle.
 38. The surgical instrument according to claim 35, wherein atleast one of the cannula and the handle is formed from a materialselected from the group consisting of: stainless steel, platinum, andpolyetheretherketone.